Pest'Stop 2000 is a proven best seller, an effective defence against mice, rats, ants and most other crawling insects. It uses fluctuating ultrasonic waves that make a noise beyond the human hearing range, but within a frequency that is uncomfortable to many rodent and insect pests. Pest'Stop 2000 generates enough protection for about a 186 square metre area (2,000 sq ft). Clean and chemical free. Indoor use only. Dimensions: H 23cm(9in) x W 9cm(4in) x D 18cm(7in).